A camera lens (also known as photographic lens or objective lens) is an assembly of optical lenses used in conjunction with a camera body to make images of objects either on photographic films or on other image storage media. Many of the camera lenses available today can be interchanged with lenses of different focal lengths, apertures, or other properties. When camera lenses and other camera equipment are not in use, they are optimally stored at a relative humidity (RH) of between 35% to 45%.
When a camera lens is detached from a camera body and placed in storage, moisture may build up on the many optical elements inside the lens and may lead to the growth of fungus inside the lens and on the optical elements, thereby impairing the optical performance of the lens in humid climates. Likewise, a camera body in storage with its lens detached may be susceptible to moisture buildup on its inner optical elements and mirror assembly. Temperature change may also cause moisture buildup inside the lens and the camera. Condensation will form when warm humid air comes into contact with cool objects. For example, when a user comes indoors after using a lens in the cold outdoors, the temperature and RH change would cause condensation build up inside the camera body and the lens. Therefore, there is a need to reduce the moisture in the camera body and the lens.